1. Field of the Invention
This invention relates to a sheet stack ejector mechanism for a sheet sorter, and more particularly to a sheet stack ejector mechanism for use in a sheet sorter, which is provided with a plurality of bins each of which receives a plurality of sheets discharged from an image recording apparatus such as a printer, a copier or the like and forms thereon a stack of sheets, in order to eject the sheet stack on each bin toward a post handling mechanism such as a punch, a stapler or the like which is movable up and down along the array of the sheet inlet ends of the bins.
2. Description of the Related Art
As disclosed, for instance, in Japanese Unexamined Patent Publication No. 4(1992)-43089, there has been known a sheet sorter in which a plurality of recorded sheets discharged from an image recording apparatus such as a printer, a copier or the like are distributed to a plurality of bins or sort trays in sequence to form a stack of sheets on each bin by a sheet distributor called an indexer and when the number of the sheets stacked on each of the bins reaches a predetermined value, the sheet stack on each of the bins is stapled by a stapler which is movable up and down along the array of the sheet inlet ends of the bins and in a horizontal direction along the edge of each bin.
Accordingly when stapling the sheet stack, it is necessary to eject the sheet stack on a selected one of the bins toward the stapler. For this purpose, conventionally, each bin is arranged to be movable toward the stapler and the selected bin is moved toward the stapler to bring the sheet stack thereon to the stapler, or a sheet stack ejector is provided for each of the bins.
However with the arrangement where each of the bins is movable toward the stapler, provision to prevent interference between the bin and the stapler must be made. Further either of the conventional structures complicates the structure of the sorter and its drive system.
Further, in the case where each bin is provided with an ejector, it becomes difficult for the ejector to eject the sheet stack on the bin when the bin is deflected or deformed.